I now have three cheap bipods from Amazon and I thought it might be helpful to post a quick review.
First up is £33 - "Zeadio Carbon Fiber Pivot Tiltable Bipod with Sling Mount (6"- 9")" (Amazon product ASIN B07JLP31ZF). I bought this a couple of years ago and it's had a reasonable amount of use. It's pretty good. It's the only one of the three that has a stud-mount. Weight is 328g. It has spring-loaded tilt (tick) but does not swivel (I don't mind). Fixing is a bit of a faff but I guess it's the same with any stud-fitting - I haven't tried others so I can't say. It's very secure once fitted. The only problems have been very minor. One of the strips of foam betwen bracket and stock came loose but I replaced it. The swivel-lock loosens easily and needs frequent tweaking to keep it tight. The legs sometimes don't lock when extended and need a bit of a wiggle. I would buy another one.

Second is £26 - "Nabila Bipods for Rifles 6 to 9 Inches Swivel Tiltable Quick Release Picatinny Mount Tactical Bipod" (Amazon product ASIN B08FQMYP4Q). I bought this, and the one below, because I wanted a Picatinny fitting to make it faster to attach/detach. It's a tiny bit heavier at 354g (plus it needs a rail, obvs, which adds weight). I have only just bought this so my review is not based on any shooting experience - just fitting it and testing it out in the house. It's stunning value for money - solidly machined our of aluminium and steel. Everything works exactly as it should and it's way more robust than I expected. It tilts and swivels and you can lock it using a large knob underneath. Tilt is quite limited and not spring loaded. Legs lock in multiple positions (but although I know this is a common feature, I don't really get why anyone wants it). Legs are unlocked with a button on each. They extend and retract without spring tension. It's really impressive and would be a good buy, but I prefer the next one.

The last one is £30 "Zeadio Tiltable Bipod F19 series, 8 to 11 Inches" - Amazon product ASIN B0C5LMJWXZ. This is the heaviest at 374g. It is taller than the other two but I never use the minimum height on my existing bipod so that's ok for me. Build quality is again astonishingly good for the money. The rifle that I'm testing them with (Howa 1500 .223 20 inch varmint in MDT LSS-XL chassis) is not light and I have absolutely no worries about using any of these bipods with it. It has very good tilt and swivel (although not spring-loaded, which I prefer) with a good locking lever. Legs lock in multiple positions and are unlocked by pulling them down. Legs extend against spring tension and therefore retract automatically when the release lever is pressed.

In summary, I think you'd be happy buying any one of these. I was thinking hard about buying something more expensive, but I'm very glad I didn't.
First up is £33 - "Zeadio Carbon Fiber Pivot Tiltable Bipod with Sling Mount (6"- 9")" (Amazon product ASIN B07JLP31ZF). I bought this a couple of years ago and it's had a reasonable amount of use. It's pretty good. It's the only one of the three that has a stud-mount. Weight is 328g. It has spring-loaded tilt (tick) but does not swivel (I don't mind). Fixing is a bit of a faff but I guess it's the same with any stud-fitting - I haven't tried others so I can't say. It's very secure once fitted. The only problems have been very minor. One of the strips of foam betwen bracket and stock came loose but I replaced it. The swivel-lock loosens easily and needs frequent tweaking to keep it tight. The legs sometimes don't lock when extended and need a bit of a wiggle. I would buy another one.

Second is £26 - "Nabila Bipods for Rifles 6 to 9 Inches Swivel Tiltable Quick Release Picatinny Mount Tactical Bipod" (Amazon product ASIN B08FQMYP4Q). I bought this, and the one below, because I wanted a Picatinny fitting to make it faster to attach/detach. It's a tiny bit heavier at 354g (plus it needs a rail, obvs, which adds weight). I have only just bought this so my review is not based on any shooting experience - just fitting it and testing it out in the house. It's stunning value for money - solidly machined our of aluminium and steel. Everything works exactly as it should and it's way more robust than I expected. It tilts and swivels and you can lock it using a large knob underneath. Tilt is quite limited and not spring loaded. Legs lock in multiple positions (but although I know this is a common feature, I don't really get why anyone wants it). Legs are unlocked with a button on each. They extend and retract without spring tension. It's really impressive and would be a good buy, but I prefer the next one.

The last one is £30 "Zeadio Tiltable Bipod F19 series, 8 to 11 Inches" - Amazon product ASIN B0C5LMJWXZ. This is the heaviest at 374g. It is taller than the other two but I never use the minimum height on my existing bipod so that's ok for me. Build quality is again astonishingly good for the money. The rifle that I'm testing them with (Howa 1500 .223 20 inch varmint in MDT LSS-XL chassis) is not light and I have absolutely no worries about using any of these bipods with it. It has very good tilt and swivel (although not spring-loaded, which I prefer) with a good locking lever. Legs lock in multiple positions and are unlocked by pulling them down. Legs extend against spring tension and therefore retract automatically when the release lever is pressed.

In summary, I think you'd be happy buying any one of these. I was thinking hard about buying something more expensive, but I'm very glad I didn't.
